LMP Seminar: Guided by curvature: coupling curvature and active forces to shape and propel cells

Eukaryotic cells control their shapes in order to fulfill different functions. The forces that deform the cell membrane arise from chemical energy that is converted to mechanical forces, mostly in the cytoskeleton. How cells control the location and timing of these forces in order to achieve their desired shape and dynamics is still an open puzzle. We have been exploring the idea that curved membrane proteins that recruit the acto-myosin cytoskeleton, provide the mechanism for the self-organization of the cytoskeleton and spontaneous formation of cellular shapes. This coupling, between curvature and active forces, was found to give rise to different types of instabilities and patterns. However, most of these results were limited to the linear regime, and we only recently started exploring the behavior of highly deformed shapes. We find that the proposed mechanism may explain some of the striking features of cells, such as the sheet-like ruffles and the lamellipodia of spreading (adherent) cells. We find that it may even contain the minimal ingredients to give rise to motile phenotypes.